NATURAL CRYSTALS SELECTION PROCESS FOR NEUTRON-DIFFRACTION APPLICATIONS

This work aims to show a selection process for natural crystals that c onsiders the major characteristics and performance as gratings for neu tron monochromators using the neutron diffraction technique. A total o f 19 crystals have been selected and classified regarding their adequa cy for use as neutron diffraction devices. Applying special criteria, method and the rocking curve technique, the measurements have been per formed and the theoretically available values compared with the experi mental results, obtained directly from a neutron diffractometer in ope ration at the IEA-R1 (5 MW) nuclear research reactor. The choice for n atural crystals, expanding the operational range of the neutron diffra ction instruments, is related with the purpose of getting monochromati c neutron sources suitable for the applications. The neutron has prove d to be the most powerful microscopic testing particle in condensed ma tter studies and in many other areas of application. (C) 1998 American Institute of Physics. [S0034-6748(98)01809-7]